1. Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing the same.
2. Description of the Related Art
Conventional processes aiming at gettering effects include intrinsic gettering (hereinafter, referred to “IG”) which uses oxygen precipitate defects 100 in a semiconductor substrate 101 of a semiconductor device, for example, an n-channel vertical MOSFET, as shown in FIG. 30. The oxygen precipitate defects 100 are served as a gettering layer which can getter defects in an element formation region 102.
In the IG, in order to improve the gettering effects to make better the quality of gate film of the semiconductor device and the reliabilities of elements formed therein, it is necessary to increase the oxygen concentration in the semiconductor substrate.
This method, however, as shown in FIG. 31, causes the resistance rate of the substrate to increase with the growth of the oxygen concentration of the substrate. This increase of the resistance rate makes increase the on-resistance of the vertical power semiconductor device, the substrate of which is served as a current path, causing the loss of the device to be increased.